Folding table



Aug. 23, 1938. u. k. JOHANNSEN FOLDING TABLE Filed July 17, 1936 lll l INVENTOR. U0 0 K. Jo/m lwvs EM,

' ATTORNEY.

Patented Aug. 23, 1938 UNITED STATES PATENT OFFICE FOLDING TABLE Application July 17, 1936, Serial No. 91,023

4 Claims.

My invention broadly relates to portable folding tables of the fully automatic type and is more particularly concerned with a collapsible ironing board stand comprising a three legged chassis in which the legs are adapted to compactly fold flatwise underneath one face of such board and to be manipulated in a simple manner.

A pair of complementary or so-called rear legs have one end thereof directly pivoted to the top board and a single inclined or so-called front leg may be similarly attached in substantial alignment with the axis of the rear leg pivots. All my rigid legs are positively actuated in unison between their respective erected and collapsible positions by the use of a novel actuating gear.

Such controlled movement is herein brought about by a manipulative primary toggle linkage of which one free link end is pivoted to the rear leg structure intermediate the ends thereof and the other free end of which linkage is pivoted underneath the board. The inclined front leg is in turn pivotally hooked up by an auxiliary toggle linkage that extends between said rear leg structure and the floor contacting end of the 5 front leg.

Stop means prevent said auxiliary linkage from reaching full toggle alignment in both the collapsed and erected table positions. By this means, the primary linkage may be freely manipulated through a wide angular range Without being stalled by its cooperating linkage.

In addition, my pair of rear legs are equipped with pivotally offset brace straps which bring about a lateral spread on part of the floor contacting leg ends simultaneous with the unfolding thereof, The actuating gear herein resorted to is especially suited for an understructure comprising wooden slats that may be operatively interconnected by simple hardware. Each such rigid table leg combines ample stiffness with low chassis weight that shall not prove burdensome to women when carried to or from a storage closet.

The object of the present invention is to provide for a sturdy folding table of the character indicated and one possessing comparatively few essential pivotal points that are not likely to become rickety from wear after extended use or allow the superstructure to sway abnormally under its anticipated loading. My table improvements Fig. 1 represents an elevational side view of an erected ironing board assembly equipped with my devices, and Fig. 2 is a rear end View thereof.

Figs. 3 and 4 respectively, show a side and a bottom view of my chassis when fully collapsed.

Figs. 5 and 6 are fragmental details respectively taken along lines 55 and 6-t of Fig. 1.

Referring more specifically tothe drawing, the numerals l0 and Il respectively designate a pair of laterally spaced rear legs. The upper end of each such leg is pivoted at l2 to one board face l3. An intermediate pivot I4 is also located between the respective ends of each rear leg.

This rear leg structure is preferably of a type in which the floor contacting ends are widely spread apart into the Fig. 2 position when the chassis is unfolded. To this end, I may resort to complementary brace straps such as l5 of which one end is pivoted to a rear leg while each opposite strap end is pivotally attached by a metal bracket to said one board face at l6 but in an axially offset relation to the corresponding rear leg pivot l2. When collapsed, the rear legs will then fall within the board width confines in the Fig. 4 manner.

My primary or rear leg toggle linkage is of the jack-knife type and may comprise a pair of strutlike links such as ll having one of their respective free ends attached to an associated intermediate pivot M, as shown. The opposite link ends are pivotally adjoined at ill to a common guide link 19, preferably made out of a strip of wood and the free end of which guide link is pivoted to the board face at 20. The pivot i8 is purposely disposed between the ends of such adjo-inecl toggle links to provide for a strutlike link extension 2| arranged to thrust as a prop agency against the board face in erected leg position. The guide link extension 22 is thereby kept spaced outwardly away from said face and its terminal preferably provided with a cleared loop or finger piece 23 by which to swing the link l9 through a wide angle of approximately 180 into its folded position 18. If preferred, the spaced link extension 22 may as a handle, be directly grasped to perform a like function.

The inclined front leg 24 may be pivotally attached to the board coincident with the rear leg pivot I2. As depicted in Figs. 2 and 4, said wooden front leg may be bifurcated by the use of companion slats of which the branched ends respectively lead to one of the complementary pivots l2 (see Fig. 4). A foot pivot 25 is located closely adjacent to the converging lower or floor contacting end of the leg 24. An auxiliary toggle lug 253.

linkage of the collapsible type interconnects said pivot 25 with the intermediate pivot i l and as such, may comprise a pair of relatively short link components 26 and corresponding relatively long or tension rod components 271 that are jointed at 28, preferably by the use of a loose slot connection.

As indicated in Fig. l by a dotted and dashed reference line A, the components of said auxiliary linkage when extended, are prevented from reaching their respective aligned dead center positions by the use of a common stop lug 2e. Such lug preferably spans the links 26 and is made to abut the front leg. The linkage thereby obviates a stalling of the primary linkage when the erected table legs are to be collapsed and said stop lug precludes such buckled toggle dropping through the alignment position A even should the erected table legs be turned upside down during the folding thereof.

As a further feature, it is preferred to form my complementary tension links 2i out of a onepiece metal rod that is given a bail shape (see Figs. 4 and 5) of which the intermediate nose portion 28 is threaded through the link slots while the bail terminals are each outturned into headed trunnions (see Fig. 6) that respectively constitute the intermediate pivots M. The end of the wooden link I1 may be metal sheathed by an apertured cap 30 to reduce trunnion wear.

The mode of folding my table legs is indicated by dotted lines in Fig, 1. In erected table position, the guide link I9 is directed rearwardly toward the pivot l2 and this brings the link extension 25 into abutment with the board face I3. The primary linkage then stands buckled through its dead center position and by virtue of the fixed bracket pivot 28, the rear legs l0 and l I will be rigidly held against collapse. The extended auxiliary toggle becomes tensioned when the ironing board is loaded downwardly but the linkage components are not allowed to assume extended alignment because of the stop The weight of the toggle links 26 and 2'! are kept relatively light so as not to draw; the front and rear legs together. When erected, the board is kept exceptionally rigid under load, partly because the foot pivot 25 is located near the floor contacting end of the inclined leg 24 rather than in the mid region thereof where a certain amount of lateral flexure would be expected.

A grasping of the finger piece 23 allows the link Hi to be swung into its dotted depending position of Fig. 1 when the auxiliary linkage will partially collapse as shown in dotted outline and thereby carry the front leg toward the board in unison with a similar rear leg movement. When the primary toggle joint i8 reaches its outermost position i8, the understructure assumes the folded Fig. 4 position. In that relationship, the stop lug 29 abuts a portion of the front leg 24 and again prevents the secondary toggle from reaching its inverted dead center position; hence, the linked understructure is kept free to unfold by a reversal of the described guide link movements without any interlocking effects.

A noteworthy attribute of the present table structure lies in its relatively simple linkage adapted to automatically unfold from a centralized manipulative point such as the link l9, and still bring about a spreading of the rear legs. In erected position, the several legs are automatically retained without need of any supplementary latch device. In addition, the auxiliary co-llapsible toggle linkage is not dependent upon the use of a loose ended tension rod of the conventional slip type likely to become entangled when a collapsed table is carried about. When folded, the board may be conveniently hung up by the forwardly overhanging loop 23.

Other advantages inherent in my table chassis are believed apparent to those skilled in this art, it being obvious that the same underlying structural principles may be used in associations other than for ironing boards, and that various modifications in design may readily be resorted to in likewise carrying out the illustrative embodiment, all without departing from the spirit and scope of my invention, heretofore described and more particularly pointed out in the appended claims.

I claim:

1. In a collapsible table or the like adapted to unfold into erected position, a top board, a front leg having one end region pivoted to one board face, a foot pivot carried by the opposite end region of the front leg, a rear leg structure also pivoted to the board face, supplementary pivot means located on said structure between the ends thereof, a primary toggle linkage including a strutlike link which intermediate its ends is pivotally jointed to one terminal region of a manipulative guide link to provide for a strutlike link extension, one end of the strutlike link being mounted on the supplementary pivot and the opposite terminal of the guide link being pivotally attached to said face to permit of swinging the jointed end of the guide link between extreme shift positions respectively lying alongside said face forwardly and rearwardly of such pivotal attachment, the strutlike link extension being disposed to thrust against the board face to retain the erected rear leg structure against collapse when the toggle linkage assumes a rearward position and which extension spacedly holds the jointed end of the guide link away from said face, a cooperative auxiliary toggle linkage comprising a pair of jointed links pivotally suspended between the foot pivot of the erected frontleg and the retained rear leg structure, and stop means interposed between the front leg and one such suspendedlink serving to prevent toggle alignment with the other suspended link, the toggle joint of such auxiliary linkage being arranged to automatically recede from said face when the guide link is swung away from its extreme rearward position.

2. In a collapsible table or the like adapted to unfold into erected position, a top board, a front leg having one end pivoted to the board, a footv 'a rear leg structure also pivoted to the board,

supplementary pivot means located between the ends of said structure, manipulative link means extending between the supplementary pivot and the board serving to guide the rear leg structure from collapsed into a retained erected position, a cooperative toggle linkage comprising a pair of jointed links pivotally suspended between the foot pivot of the erected front leg and the retained rear leg, and stop means for one such suspended link serving to prevent toggle alignment with the other suspended link, the interposed toggle joint thereof being arranged to automatically recede from said face and being operative by the manipulative link means toinitiate a collapsing movement on part of the several erected legs.

3. In a collapsible table or the like adapted to unfold into erected position, a top board, a front leg having one end region pivoted to the board, a foot pivot on the opposite end region of the front leg, a structure comprising a pair of rear legs also pivoted to the board, a supplementary pivot located between the respective ends of each rear leg, manipulative link means extending between the supplementary pivots and the board serving to guide said rear legs between collapsed and erected positions, and a toggle linkage disposed between the foot pivot and said pair of rear legs whereby the front leg is actuated in unison with the guided rear legs, said linkage comprising a pair of jointed link components of difierent lengths of which the free end of the shorter link component is mounted on the foot pivot and the free end of the longer link component is given a unitary bail shape of which the bifurcated terminal regions are respectively attached to a different rear leg and arranged to constitute the aforesaid supplementary pivots thereof and the medial nose region of which bail pivotally engages the other end of the shorter link component to constitute the toggle joint of such linkage.

4. In a collapsible table or the like adapted to unfold into erected position, the combination of a top board, a front leg having one end region pivoted to one board face, a foot pivot carried by the opposite end region of the front leg, a rear leg structure also pivoted to said board face,

supplementary pivot means located on said structure between the ends thereof, a primary toggle linkage including a strutlike link having one end pivotally jointed to one terminal region of a manipulative guide link, the other end of the strutlike link being mounted on the supplementary pivot and the opposed terminal of the guide link being pivotally attached to said face to permit of swinging the jointed end of the guide link through its aligned dead center into a buckled toggle position lying rearwardly of such pivotal guide link attachment and wherein said toggle linkage serves to retain the erected rear leg structure against collapse, a cooperative auxiliary toggle linkage comprising a pair of jointed links of difierent lengths pivotally suspended between the foot pivot of the erected front leg and the retained rear leg structure, and stop means operatively interposed between the shorter link and said front leg serving to prevent toggle alignment with the longer link, the stop means being disposed to automatically recede from said face when the guide link is swung away from its buckled position and the respective linkages being so arranged that the primary linkage when manipulated cannot become stalled because of link alignment on part of the auxiliary linkage.

UDO K. J OHANNSEN. 

